Computer applications are created using programming languages. These programming languages include human-readable text, which is translated by a compiler to generate machine-readable instructions. In particular, the compiler translates each line of the programming language into a sequence of machine-readable instructions, which perform the logical task described by the line of programming language code.
During the course of programming, errors may occur due to programmer error. These errors include either syntax errors or logic errors. Syntax errors are caught by the compiler, which refuses to generate machine instructions for a line of programming language that it does not understand. Logic errors are caught by detecting that the program does not perform as expected, often resulting in program exceptions or incorrect behavior. While syntax errors can be corrected by determining the correct syntax, logic errors are often much more difficult to ascertain. For this reason, a special class of computer programs has been developed. These programs are called debuggers. One example of a debugger is described in U.S. Pat. No. 4,636,940, entitled “Logic Analyzer Using Source Programs Or Other User Defined Symbols In The Trace Specification And The Trace Listing”, issued Jan. 13, 1987, which is hereby incorporated herein by reference in its entirety. A debugger allows the user to trace through the users' own program, while it is executing on the computer, to determine the instance or instances where the logical flow of the program is incorrectly designed.
A debugger uses debugging information to debug the state of variables at runtime. This debugging information is generated by the compiler and describes how the variables of the application are stored and what fields the variables contain. One example of a technique used by a compiler to generate this debugging information is described in U.S. Pat. No. 5,715,460, entitled “Template Based Facility For Formatting Compiler Output”, issued Feb. 3, 1998, which is hereby incorporated herein by reference in its entirety.
The amount of space required to store the debugging information can become large, particularly if a large number of variables are used or if the variables contain a large number of fields. When many programs are compiled with debugging information, the storage size required to keep these applications in a debuggable state can become onerous. The ability to reduce the amount of space used to store the debugging information is, therefore, desirable.
Several techniques have been employed in an effort to reduce the amount of debugging information. Examples of these techniques are described in, for instance, U.S. Pat. No. 6,226,786, entitled “Minimizing Debug Information For Global Types In Compiled Languages”, issued May 1, 2001; Japanese Patent No. JP10289109A, entitled “Compiling Control Method, Compiling Device and Recording Medium”, issued Oct. 17, 1998; and U.S. Pat. No. 5,680,622, entitled “System And Methods For Quickly Detecting Shareability Of Symbol And Type Information In Header Files”, issued Oct. 21, 1997, each of which is hereby incorporated herein by reference in its entirety. One or more of the techniques determine common information between application segments, which are linked or compiled together to create a single executable. The identification and use of the common information reduces the need for duplicative information, thereby reducing the amount of space used to store the debugging information.
However, a need still exists for a capability that facilitates a reduction in the amount of debugging information, and therefore, the amount of storage space, when applications are independent of one another. In particular, a need exists for the determination of common information for applications that are not linked, compiled or integrated with one another.